This invention relates to driver units employed for horn type loudspeakers, and more particularly to an improvement of an equalizer in a driver unit.
A driver unit is used to drive a horn type loudspeaker. A driver unit in which tones are produced from the concave side of a dome-shaped diaphragm is well known in the art as a driver unit having high performance. However, the driver unit of this type still suffers from a disadvantage that the spread of produced tones in the high tone range connot reach its ideal value because of the air which is leaked out of the gap between the inner side of the voice coil and the center pole. In order ot overcome this difficulty, or to eliminate the effect of the air leakage between the inner side of the voice coil and the center pole, a method in which slits are formed in the peripheral portion of the equalizer has been proposed. However, in practice, even with the slits, it is still difficult to improve the spread of produced tones in the high tone range and to provide a smoothly extended frequency response characeristic.